Detergent compositions useful for cleaning purposes, such as laundering of fabrics, have commonly utilized a variety of surfactants.
The ability of surfactants to clean a large variety of soils and stains from fabrics present in the typical load of laundry is of high importance in the evaluation of detergent performance. Unfortunately, the relative ability of each surfactant to meet various performance criteria is among others depending on the presence of cosurfactants.
The recent trend towards partial or total replacement of Linear alkyl benzene sulfonate surfactants (LAS) has urged the detergent formulators to rebalance their formulations with different surfactants. For example, quaternary ammonium salts are less efficient in boosting the greasy cleaning performance in Nil-LAS formulations.
There is thus a standing desire for performance and flexibility reasons to make available a surfactant system capable of providing optimum detergency performance which is equivalent to that of LAS-containing detergents.
The above objective has been met by a surfactant system comprising anionic surfactants selected from the group consisting of alkyl alkoxylated sulfates and alkyl sulfates, said surfactant system further comprising a cosurfactant selected from the group of primary or tertiary amines.
It has been surprisingly found that detergent compositions containing said surfactant system exhibit detergency performance equivalent to that of LAS-containing detergents.
In addition, it has been found that a small amount of certain primary and tertiary amines according to the present invention constitutes an efficient and compatible sud suppressing system. This additional benefit allows to use the amines in a dual function, e.g. surfactant and suds suppressor, thereby facilitating the formulation of concentrated liquid detergents.
Liquid detergent compositions formulated with said surfactant system are extremely useful when the liquid detergent compositions are in direct contact with the fabrics such as during pretreatment.
Amines have been described in the art in liquid detergent compositions. EP 160 762, EP 137 615 and EP 137 616 disclose liquid detergents which comprise cyclohexylamine. EP 177 165 discloses detergent compositions which comprise anionics, cellulase and a variety of primary, secondary, tertiary and quaternary amines. EP 11 340 discloses soften through the wash detergent compositions which comprise tertiary amines and clay. DE 32 07 487, GB 2 094 826, GB 2 095 275 and EP 137 397 disclose compositions which comprise anionics and quaternary amines. EP 120 528 discloses compositions comprising anionics, as well as tertiary amines. EP 26 528 and EP 26 529 disclose compositions comprising anionics and quaternary amines. Detergent compositions containing 1) primary or tertiary amines of the type useful herein in combination with 2) oleoyl sarcosinate are disclosed in U.S. patent application Ser. No. 08/252,127, filed Jun. 1, 1994. Compositions of this invention may or may not contain oleoyl sarcosinate surfactants.